Half a century after the first mobile phone call, the handheld device we keep in our pocket is poised to play a pivotal role in earthquake detection. On 25 October 2022, a 5.1-magnitude earthquake struck the Bay Area of California. The shaking was not particularly damaging, but it was notable for other reasons too: warning alerts were sent to many people on their phones just seconds before the shaking started. Meanwhile, residents closer to Los Angeles were able to prepare for a magnitude 5.2 earthquake on 6 August 2024.
Google has also collaborated with the United States Geological Survey (USGS) and several Universities in California to develop an early warning system for earthquakes, giving seconds of warning before a quake hits, which could be long enough to dive under a desk, slow down a train, or prevent a plane from taking off – potentially saving countless lives during bigger earthquakes.
The system uses information from two sources. In its early days, it was based on a network of 700 seismometers spread across the state of California and neighboring states. Now, Google has expanded this network by using smartphones running its Android operating system. Almost all Android phones carry an accelerometer, a tiny device that detects movement. The first waves of an earthquake can trigger an accelerometer to send its data to Google’s Earthquake Alerts System.
When enough phones detect these shocks – in the hundreds of thousands or even more – the system can triangulate the location of an earthquake and broadcast alerts to phones in the path of the shaking. The radio signals travel faster than the seismic waves, so the alerts often arrive before the shaking.
Today the system is operating in more than 90 countries that are prone to earthquakes and is credited with protecting millions of people around the globe. The system is not without its flaws, especially in terms of its ability to work in remote areas and detect offshore earthquakes. Nonetheless, it represents a great leap forward in earthquake safety. These phones don’t just keep us connected, but also free from the dangers all around us, especially the ones lurking beneath our feet.
Work Cited:
- Johnson, Vivienne. “The Phones That Detect Earthquakes.” BBC Future, BBC, 5 Apr. 2023, www.bbc.com/future/article/20230405-the-phones-that-detect-earthquakes.
- Chang, Alicia, and Rong-Gong Lin II. “What Makes an Earthquake Deadly? These Are the Things That Matter.” Los Angeles Times, 7 Feb. 2023, www.latimes.com/science/story/2023-02-07/what-makes-an-earthquake-deadly-these-are-the-things-that-matter.
